I usually have been, but at the moment my salad spinner is full and I have a HUGE thing of spring lettuce mix that says "pre-washed". Do I really have to wash it? It is Earthbound farms and organic. Hm...I haven't been able to find much info on line about this...
Earthbound Farms, although certified "organic" by USDA standards, is a large-scale industrial farming operation. Because of this, your greens pose a higher risk of contamination of harmful bacteria like e.coli. In fact, the e.coli outbreaks from spinach a few years back were from Earthbound Farms (http://www.washingtonpost.com/wp-dyn/content/article/2006/09/15/AR2006091500865.html).Organic greens from a small, local farm in your area may have a bit of dirt and visible bugs, but are less likely to pose any significant threat to your health.
The short answer is yes, wash your greens. The better solution is to try to buy your vegetables from a small, local organic farm whose growing and harvesting methods reduce the chance of harmful bacteria contamination. Read more from Michale Pollan: http://michaelpollan.com/articles-archive/the-vegetable-industrial-complex/
Recipe for Beets? 15 Answers